Josh Lewis and Aaron Zimmer are 11 years old. They go to the exclusive, private Huckley School in New York. Josh"s father has just left home for a trial separation from his wife. This has upset Josh more than his sister Heather, who says she is "nearly thirteen and emotionally fourteen". Even more upsetting are his friend Aaron"s experiments with computer time travel. Aaron has discovered how to travel into the future and, more importantly, into the past. This book is the story of t"heir adventures in Cyberspace.